Apparatus for grinding or polishing flat glass



May 23, 1950 LABBY El AL APPARATUS FOR GRINDING 0R POLISHING FLAT cuss 2 Shets-Sheet 1 Filed Aug. 5, 1947 Inventors Attorneys.

May 23, 1950 L. LABBY AL APPARATUS FOR GRINDING OR POLISHING FLAT GLASS 2 Sheet s-Sheet 2 Filed Aug. 5, 1947 X & Inventors fimm ZZ/ A H urneyS Patented May 23, 1950 APPARATUS FOR OB POLISHING FLAT G Leon Labby, Franiere, Belgium, and Pierre Bonsseau, Thourotte, France, assignors, by mesne assignments, to Pilkington Brothers Limited, kirtierpool, England, a corporation of Great Application August 5, 1947, Serial No. 766,194 In France July 13, 1943 Section 1, Public Law 690, August Patent expires July 13, 1963 4 Claims. (01. 51-112) This invention relates to apparatus for grinding, lapping, or polishing the surface of flat glass, and which act simultaneously in continuous progression on the two faces of a continuous ribbon of glass, in accordance with the method known generally as the continuous grinding-polishing of two faces.

In the known apparatus of this kind, work of grinding and polishing is carried out by two series or lines of tools situated on either side of the horizontal ribbon of glass, the tools of the upper series being independent of those of the lower series in that each series possesses its own means for the support. the adjustment in position and the possible removal of the tools. Outside of this independence the structure of the known apparatus and, more particularly, the method of supporting the tools, should it be necessary to move them aside from the operative position for the purpose of permitting of their possible repair or renewal, makes it necessary to displace them in a vertical direction, which, so far as the lower tool is concerned, calls for interruption in the forward movement of the ribbon of glass in order to permit of vertical lifting and removal of the tool or even only of access thereto. It is not to be ignored, however, that the technical basis and the economy of the method reside essentially both in the continuity of the ribbon of glass as well as its progression.

The invention proceeds from an entirely different conception to that in the above, which enables in principle the limitations, which have just been referred to, to be avoided.

According to this invention the apparatus for carrying out the continuous grinding and polishing of two faces of flat glass simultaneously is characterised by the fact that it comprises means which enable the tools, or only certain of them, to be moved into the line of operation and to be withdrawn therefrom by a movement parallel or substantially parallel to the surface of the glass, without it being necessary to interrupt the continued progress of the advancing ribbon of glass.

This displacement of the tools for the purpose of moving them into operation or withdrawing them is effected by a translatory movement performed transversely to the longitudinal line of their working position, for example perpendicularly thereto.

Within the scope of the invention the move ments of the two tools of the same pair can with advantage be coupled together or rendered synchronous, in such a way that their relative positionisnotmodified.

This linking together of the movements can be accomplished either by a common actuation or by the combination of the two tools on the one base or support.

A particularly advantageous embodiment applying to this second solution consists in combining the upper and lower tools of the same pair in one working unit constituted by a C-shaped support movable transversely and parallel to the ribbon of glass and carrying together with these tools all the equipment for the actuation thereof and for feeding abrasive thereto.-

The C-shaped support rests by means of runners or rollers on two fixed slides parallel to the surface of the glass and disposed, for example, perpendicularly, to the line of work, in such a way that by displacement of this support on the slides the two tools can be moved into the line of work or removed therefrom by the same translatory movement without it being necessary to interrupt the continued forward movement of the glass. In particular it is sufiicient for the withdrawal of the tools to move away from the ribbon of glass by a very small amount either each of the two tools or even only one of them in order to enable the total withdrawal of the working unit to take place readily with great rapidity and without risk of damaging the glass, as the tools are continuously guided during this movement.

In certain cases, and in particular when comparatively thin glass is concerned, the withdrawal of the lower tool presents the problem of supporting the ribbon of glass, as during the working period this tool at the same time forms a supporting table for the glass. However, in the apparatus according to the invention the lower tool can be withdrawn by translatory motion in the plane of contact itself, that is to say, without suddenly interrupting the contact with the u complete surface of the tool. The ribbon of glass only being released gradually over an increasing fraction of its width, it is possible to substitute synchronously for the supporting table which moves away auxiliary supporting or guiding members, such as a supporting plane for the lower face carried by a carriage and/or a pressure plane for the upper face carried by the same carriage Fig. 1 is a side elevational view of the apparatus.

Fig. 2 is a front view.

In these figures, I designates the C-shaped support, which rests by means of runners 2 on slides 3 carried by beams 4-4, which in turn are mounted on stone pillars 5-5 arranged perpendicularly to a plane in which the glass ribbon 8 is advanced, which ribbon is; moved by the rollers turning on a support 8 which is independent of the support i.

The two tools, the lower one 9 and the upper one ID, are constituted in the known manner by stones furnished with wipers.

The lower tool 9 which, in the operative position, acts at the same time as a table supporting the glass rests by a socket on the lower arm of the support and is actuated by a motor H.

The equilibrium of this lower tool is ensured by a counterweight l2 acting thereon through the medium of a lever l3. The upward and downward movement of this tool is effected by hand by means of a graduated wheel l4 or by the action of a motor.

The upper tool It mounted on the upper arm of the C is set into rotation by a motor I 5, and its upward and downward movements are ensured by a manually operated winch It or by a motor The feeding of these tools with suitable abrasive material is carried out by means of two pipes A hopper 20 integral with the C-shaped support receives the used abrasive and if necessary the particles of glass. This hopper forms a single slope towards the side of the pit, and it terminates in a pipe 2|, by which the liquid is evacuated to a second pipe 22 of larger cross-section, which joins up with the first one and is fixed in the wall of the side of the pit.

To the side of the vertical upright of the c-shaped support a movable false bottom 23 covers the lower gallery 24 of the apparatus. To displace one of the grinding tools it is sumcient, therefore, to lift the part of the movable false bottom which is situated behind this unit, thus uncovering the slides 3--3 on which the said unit can then be displaced by the: action of a motor 25 carried by the C-shaped support and operating the pinions 26-26 meshing with the racks 2'l2l mounted on the beams 4-4.

After the grinding tool has been disengaged by this movement from the general alignment it can be lifted by means of a roller hoist and conveyed towards a repair point specially equipped for the dismantling of all its parts.

Thus, the removal of the: tools in relation to the plane of the travelling glass is the only operation which requires to be carried out in the working position when it is necessary to proceed to examine or maintain the tools.

In this respect it may occur that in the units reserved for polishing purposes a breakage of greater proportions has the result of filling the felts of some of the lower tools with glass chippings. The cleaning of these, which in the known installations is a lengthy, tedious and uncertain matter, is to the contrary carried out very easily in the apparatus according to the invention, as it is sufficient to displace the contaminated units in order to proceed with a complete and rapid cleaning of the felts.

As the operations of dismantling are carried out only when the mechanism has been entirely removed from the working zone, the risk of events, consequential to this dismantling, having a detrimental efiect on the glass is practically eliminated.

Further, owing to the presence of the support common to the two tools, on the one hand the regulation of the parallel nature of these in relation to the glass necessitates only one single assembly operation and, on the other hand, the initial equilibrium of the two tools, the one above the other, as established by the designer, is maintained without possible derangement.

This permanent condition of the parallel nature of the tools in relation to the plane of the moving glass and of their reciprocal equilibrium continue to exist in themselves when it is desirable to displace the support for the purpose of adapting the working position of the tools to any possible transverse digressions on the part of the ribbon of glass during its advancing movement. Likewise, the supporting table formed by the lower tool remains continuously at the same level. In consequence the centring of the tools on the sheet for the purpose of complying with transverse diversions of the latter does not necessitate any special regulation.

It is desirable to point out on the other hand that in the apparatus known heretofore the provision of rollers ensuring the continuous movement of the glass calls for a lengthy and tedious dismantling of the device for supporting the tools. In contradistinction thereto the simple displacement of the C-shaped support in the apparatus according to the invention has the result of providing immediately in complete fashion access to these driving rollers.

To support the ribbon of glass during the absence of a lower working tool there is utilised a chassis 28 movable on the transverse rails 29 fixed on the pillars bearing the support 8. This chassis, which presents a supporting plane 28a for the glass, is made to slide progressively below the latter in proportion to the withdrawal of the working tool.

A chassis of similar design can complete the apparatus for preventing the lifting of the upper face of the glass, particularly in the case of polishing elements.

It is of interest to point out that in accordance with a complementary arrangement the control of the level of the lower element is effected by means of a removable articulated rod 30 resting on the C-shaped support. This rod terminates, to the side of the ribbon of glass, in a spherical portion 3|, whilst its outer end is furnished with an index 32 moving in front of a graduated sector 33. By moving the spherical member 3| into contact with the lower face of the glass 6, with is itself on a level with the frictional surface of the lower tool, it is possible to read instantly, with the multiplication which the lever furnishes, the level in question on the sector, the zero point indicating the theoretic level of the plane of work.

For returning to position the working unit at the proper location in the transverse direction a mark previously traced on the C-shaped support must agree with an index fixed on the slides and determining the axis of the ribbon of glass.

We claim:

1. In an apparatus of the kind described for grinding or polishing simultaneously the two flat surfaces of a continuous ribbon of glass, means for advancing a continuous ribbon of glass progressively through the apparatus, coaxial pairs of tools, the tools of each said pair coacting to opcrate simultaneously on the two flat surfaces of the continuous ribbon of glass, and supports movable individually and each supporting a pair of said tools for individually moving the said pairs of tools as aligned pairs of tools in a horizontal plane parallel to the surfaces of the glass be-- tween the operative position of said tools and a position to the side of the moving ribbon of glass.

2. In an apparatus of the kind described for grinding or polishing simultaneously the two flat surfaces of a continuous ribbon of glass, means for advancing a continuous ribbon of glass progressively through the apparatus, coaxial pairs of tools, the tools of each said pair coacting to operate simultaneously on the two flat surfaces the operative position of said tools and a position to the side of the moving ribbon of glass.

3. In an apparatus of the kind described for grinding or polishing simultaneously the two fiat surfaces of a continuous ribbon of glass, means for advancing a, continuous ribbon of glass progressively through the apparatus, coaxial pairs of tools, comprising upper and lower tools, the

tools of each said pair coacting to operate simultaneously on the two flat surfaces of the continuous ribbon of glass and the lower of said tools serving as support for the ribbon of glass on its lower surface, tracks disposed at right angles to the direction of movement of the continuous ribbon of glass advancing through the apparatus. O-shaped supports movable individually and each supporting a pair of said tools for individually moving the said pairs of tools as aligned pairs of tools in a horizontal plane parallel to the surfaces of the glass'between the operative position of said tools and a position to the side of the moving ribbon of glass, and auxiliary supporting means for supporting the ribbon of glass on its lower -surface, said auxiliary supporting means being movable into position below the ribbon of glass when any of said pairs of tools are moved out of said operative position, and movable away from the ribbon of glass when said pairs of tools are returned to said operative position.

' 4. In an apparatus of the kind described for grinding or polishing simultaneously the two flat surfaces of a continuous ribbon of glass, means for advancing a continuous ribbon of glass, progressively through the apparatus, coaxial pairs of tools comprising upper and lower tools, the tools of each said pair coacting to operate simultaneously on the two flat surfaces of the continuous ribbon of glass and the lower of said tools serving as support for the ribbon of glass on its lower surface, first tracks disposed at right angles to the direction of movement of the continuous ribbon of glass, c-shaped supports movable individually along said first tracks and each supporting a pair of said tools for individually moving the said pairs of tools as aligned pairs of tools in a horizontal plane parallel to the surfaces of the glass between the operative position of said tools and a position to the side of the moving ribbon of glass, second tracks disposed parallel to said first tracks, and auxiliaiy supporting means for supporting the ribbon of glass on its lower surface, said a y supporting means being movable on said second tracks into position below the ribbon of glass when any of said pairs of tools are moved out of said operative position, and movable away from the ribbon of glass when said pairs of tools are returned to said operative position.

LEON LABBY. PIERRE BOUSSEAU.

REFERENCES CITED The following references are of record in the file of this patent:

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